Fluorenol, also known as hydrafinil, is an

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

derivative of

fluorene Fluorene , or 9''H''-fluorene is an organic compound with the formula (C6H4)2CH2. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. It has a violet fluorescence, hence its name. For commercial pu ...

. In the most significant isomer, fluoren-9-ol or 9-hydroxyfluorene, the

hydroxy group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

is located on the bridging carbon between the two benzene rings. Hydroxyfluorene can be converted to fluorenone by oxidation. It is a white-cream colored solid at room temperature.

Toxicity

Fluorenol is toxic to aquatic organisms including algae, bacteria, and crustaceans. Fluorenol was patented as an

insecticide Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed t ...

in 1939, and is an

algaecide Algaecide or algicide is a biocide used for killing and preventing the growth of algae, often defined in a loose sense that, beyond the biological definition, also includes cyanobacteria ("blue-green algae"). An algaecide may be used for controlle ...

against the green algae ''

Dunaliella ''Dunaliella'' is a single-celled, photosynthetic green alga, that is characteristic for its ability to outcompete other organisms and thrive in hypersaline environments. It is mostly a marine organism, though there are a few freshwater species ...

bioculata''.MSDS
Its toxicity and

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive sub ...

icity in humans are unknown.

Mechanism of action

The exact mechanism of action of fluorenol is unknown. The lipophilicity of fluorenol (LogP 2.4) is higher than that of drugs like modafinil (LogP 1.7) and amphetamine (LogP 1.8), suggesting that it may penetrate the blood brain barrier more readily.

Eugeroic

A study published by

Cephalon Cephalon, Inc. was an American biopharmaceutical company co-founded in 1987 by pharmacologist Frank Baldino, Jr., neuroscientist Michael Lewis, and organic chemist James C. Kauer—all three former scientists with the DuPont Company. Baldino s ...

describing research to develop a successor to the eugeroic

modafinil Modafinil, sold under the brand name Provigil among others, is a central nervous system (CNS) stimulant medication used to treat sleepiness due to narcolepsy, shift work sleep disorder, and obstructive sleep apnea. While it has seen off-la ...

reported that the corresponding fluorenol derivative was 39% more effective than modafinil at keeping mice awake over a 4-hour period. However, after further investigation it was determined that the eugeroic activity of the fluorenol analog was likely due to an

active metabolite An active metabolite is an active form of a drug after it has been processed by the body. Metabolites of drugs An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body ...

, which they identify as fluorenol itself. Fluorenol is a weak

dopamine reuptake inhibitor A dopamine reuptake inhibitor (DRI) is a class of drug which acts as a reuptake inhibitor of the monoamine neurotransmitter dopamine by blocking the action of the dopamine transporter (DAT). Reuptake inhibition is achieved when extracellular ...

with an IC₅₀ of 9

μM The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer ( American spelling), also commonly known as a micron, is a unit of length in the International System of Uni ...

, notably 59% weaker than modafinil (IC₅₀ = 3.70 μM), potentially making it even less liable for

addiction Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use o ...

. It also showed no affinity for cytochrome P450 2C19, unlike modafinil. There is no evidence (binding assays, occupancy, predicted structure) to suggest that fluorenol acts as a 5-HT6 antagonist, contrary to some popular claims.

Sale as research chemical

The unscheduled nature of fluorenol has caused it to fall into a legal grey area in most countries. Despite being associated with modafinil, fluorenol does not bear any chemical resemblance to it, making its scheduling unimplied by analogue acts. Fluorenol is a relatively obscure compound in the research chemical market. According to an online survey with over 3000 respondents, only 2% of modafinil users have reported using fluorenol.

References

{{Monoamine reuptake inhibitors Designer drugs Fluorenes Secondary alcohols Dopamine reuptake inhibitors Biocides Algaecides Insecticides Drugs with unknown mechanisms of action

Toxicity

Mechanism of action

Eugeroic

Sale as research chemical

See also

References